This invention relates generally to electrical junction boxes, that is, enclosures in which are housed connections or splices between two or more electrical conductors, such as wires. More particularly, it relates to electrical junction boxes which are especially well-suited for subterranean use.
Generally, electrical junction boxes are well known in the art. Such boxes are used in residential, industrial and commercial installations and in such instances, are typically of a relatively small size e.g. 4xe2x80x3 in diameter and 1xe2x80x3 to 3xe2x80x3 in depth. They are normally placed in ceilings, walls, flooring, etc. to receive spliced conduits, valved conduits and other joints. Several examples of this type of junction box are known in the art as exemplified by U.S. Pat. Nos. 3,873,757; 4,244,484; 4,266,266; 4,542,437; 4,654,470; 5,382,752; and 5,541,363.
Junction boxes are also used in major installations in underground construction, where large cables are joined for high voltage lines. In such cases, the junction boxes are many times the size of the above type and may, for example, be 2xe2x80x2 to 4xe2x80x2 in diameter and 1xe2x80x2 to 4xe2x80x2 high. In the latter case, the construction and structural characteristics required for such junction boxes are significantly different than the small residential or like installations. Where such junction boxes are used exteriorly, they may be buried in the ground or mounted on a slab construction which is subsequently covered with earth, sand or the like. In addition to other factors, such junction boxes must obviously meet requirements for exposure to outdoor criteria e.g. water resistance, etc.
In the case of outdoor junction boxes, for large electrical installations, one possibility has been to construct a fixed enclosure of suitable material e.g. concrete, metal housings or the like. Apart from the cost effectiveness of such construction, there are also other considerations such as transportation, installation, etc. which add to the total economic factor for such apparatus. It would be desirable if there could be provided a junction box structure and apparatus which can readily be mounted in a subterranean location, and which can be manufactured in an economic and simple manner while at the same time providing a unit which can be readily secured in place under different locations and circumstances.
Conventionally the known junction boxes include clamps to fasten a cable therein entering the box. Typically, the boxes include xe2x80x9cknockoutsxe2x80x9d to permit reception of a conduit within the box, as such knockouts are well known in the art. Further, many known junction boxes are made from an electrically-conductive material which requires that electrical conduits be grounded thereto.
The present invention provides a junction box useful for containing electrical connections comprising a substantially cylindrical enclosure portion having a bottom surface portion, a wall portion having an inner surface and an outer surface. The wall portion defines an outer diameter, and the wall portion further comprises a top edge portion. The enclosure portion further comprises: i) a plurality of conduit receiver bosses having knock-out provisions disposed on the bottom surface portion; ii) a mount boss disposed on the bottom surface portion; iii) a plurality of protruding pins disposed on the outer surface of the wall portion of the enclosure portion; and iv) a seal means annularly disposed about the wall portion at the top edge portion of the enclosure. There is a cap portion which comprises a cylindrically-shaped inner bore which is larger than the outer diameter of the wall of the enclosure portion. The cap portion includes a plurality of angled channels on its inner surface which are adapted to receive the protruding pins. The cap portion is disposed about the enclosure portion so that the protruding pins are disposed within the angled channels.